IMMUNOGLOBULIN-G SUBCLASSES OF ANTIBODIES TO HEPATITIS-B CORE ANTIGEN IN HBS-ANTIGEN POSITIVE LIVER-DISEASES

Serum immunoglobulin G (IgG) subclasses of hepatitis B core antibody (anti-HBc) in 54 patients with different types of hepatitis B surface antigen positive (HBsAg +) liver diseases (asymptomatic carrier (ASC), acute hepatitis (AH), chronic hepatitis (CH) and liver cirrhosis (LC)) and 18 normal controls were estimated by enzyme-linked immunosorbent assay (ELISA) using subclass specific anti-human mouse monoclonal antibodies. In 11 cases, the estimations were carried out at both exacerbation and remission stages of chronic active hepatitis (CAH). In 4 cases of CAH, serial observations of anti-HBc IgG subclasses were made according to the clinical course. In 5 cases of CAH, the estimations were carried out at the HBe antigen positive (HBeAg +) stage and after sero-conversion to anti-HBe positive (anti-HBe +) stage. In ASC the main anti-HBc IgG subclasses were restricted to one subclass-anti-HBc IgG1. In AH on the other hand, all the subclasses were represented. In CH all the subclasses were detected under different diagnostic conditions but anti-HBc IgG1 was the main subclass. In LC the mean concentration of anti-HBc IgG3 was higher than the concentration of anti-HBc IgG1. In exacerbation stages of CAH, the different anti-HBc IgG subclasses had higher concentrations than in remission stages. The concentrations of different anti-HBc IgG subclasses fell just after seroconversion from HBeAg + stage to anti-HBe + stage. These data suggest that the estimation of anti-HBc IgG subclasses may be helpful in establishing the diagnosis of different types and stages of HBsAg + liver diseases.